1. Field of the Invention
This invention relates to new succinic acid derivatives with a lipid-like structure which are suitable as a skin-moisture-regulating component in cosmetic and dermatological preparations.
Keeping the skin healthy and promoting a cosmetically attractive smooth appearance and a soft feel means, above all, maintaining the natural moisture content of the stratum corneum. There are many known skin-moisturizing and moisture-retaining additives for cosmetic and therapeutic skin treatment compositions. They are generally water-soluble or water-binding substances or even hygroscopic compounds. Most of these substances have the disadvantage that, in the event of frequent use, they contribute towards even greater drying out of the skin.
Paraffin oils, triglyceride oils and waxes are distinguished by an excessively occlusive effect which seriously inhibits the transepidermal exchange of water.
2. Discussion of Related Art
The stratum corneum lipids of the human skin and also synthetic analogs of these lipids have recently become known for their effectiveness in regulating skin moisture (J. Soc. Cosmet. Chem. 40 (1989), 273-285). The synthetic lipid analogs in question are, for example, N-acyl sphingosines and fatty acid amides of 1-N-hydroxy-ethylamino-2-hydroxy-3-alkoxypropane (cf. for example EP 0 277 641, EP 0 455 429).